Porsche 959

Tuesday 9 January 2018
The Porsche 959 is a sports car manufactured by Porsche from 1986 to 1993, first as a Group B rally car and later as a legal production car designed to satisfy FIA homologation regulations requiring at least 200 street legal units be built.
When it was introduced, the twin-turbocharged 959 was the world's fastest street-legal production car, boasting a top speed of 195 miles per hour (314 km/h), with the sport model capable of reaching 197 miles per hour (317 km/h). During its production run it was hailed as the most technologically advanced road-going sports car ever built, and forerunner of all future super cars. It was one of the first high-performance vehicles with all-wheel drive, providing the basis for Porsche's first all-wheel drive Carrera 4 model. Its performance convinced Porsche executives to make all-wheel drive standard on all 911 Turbos starting with the 993. In 2004, Sports Car International named the 959 number one on its list of Top Sports Cars of the 1980s.
Development of the 959 (originally called the Gruppe B) started in 1981, shortly after the company's then-new Managing Director, Peter Schutz, took his office. Porsche's head engineer at the time, Helmuth Bott, approached Schutz with some ideas about the Porsche 911, or more aptly, a new one. Bott knew that the company needed a sports car that they could continue to rely on for years to come and that could be developed as time went on. Curious as to how much they could do with the rear-engined 911, Bott convinced Schutz that development tests should take place, and even proposed researching a new all wheel drive system. Schutz agreed, and gave the project the green light. Bott also knew through experience that a racing program usually helped to accelerate the development of new models. Seeing Group B rally racing as the perfect arena to test the new mule and its all wheel drive system, Bott again went to Schutz and got the go ahead to develop a car, based on his development mule, for competition in Group B.
Porsche developed an existing engine instead of creating a new one from scratch. The powerplant, a twin-turbocharged six-cylinder boxer engine with air-cooled cylinders and water-cooled heads, displaced 2.85 litres, about half a litre less than a contemporary 911 engine. It was coupled to a unique manual gearbox offering five forward speeds plus a "G" off-road gear, as well as reverse. The engine had originally been developed for the "Moby Dick" race car and then been redeveloped slightly for the short-lived Porsche Indy Car and several other projects before being tuned a last time for use in the 961, the 959's racing counterpart. The water-cooled four-valve cylinder heads combined with the air-cooled cylinders and sequential turbochargers allowed Porsche to extract 331 kW (444 hp) from the compact, efficient and rugged power unit. The use of sequential twin turbochargers rather than the more usual identical turbochargers for each of the two cylinder banks allowed for smooth delivery of power across the engine speed band, in contrast to the abrupt on-off power characteristic that distinguished Porsche's other turbocharged engines of the period. The engine was used, virtually unchanged, in the 959 road car as well.
To create a rugged, lightweight shell, Porsche adopted an aluminium and Aramid (Kevlar) composite for body use along with a Nomex floor, instead of the steel normally used on their production cars. The vehicle's weight of 1,450 kilograms (3,200 lb) helped to achieve its high performance level.
Porsche also developed the car's aerodynamics, which were designed to increase stability, as was the automatic ride-height adjustment that became available on the road car (961 race cars had fixed suspensions). Its "zero lift" aerodynamics were a big part of keeping it drivable. The 959 also featured Porsche-Steuer Kupplung (PSK) which was at the time the most advanced all-wheel-drive system in a production car. Capable of dynamically changing the torque distribution between the rear and front wheels in both normal and slip conditions, the PSK system gave the 959 the adaptability it needed both as a race car and as a "super" street car. Under hard acceleration, PSK could send as much as 80% of available power to the rear wheels, helping make the most of the rear-traction bias that occurs at such times. It could also vary the power bias depending on road surface and grip changes, helping maintain traction at all times. The dashboard featured gauges displaying the amount of rear differential slip as well as transmitted power to the front axle. The magnesium alloy wheels were unique, being hollow inside to form a sealed chamber contiguous with the tire and equipped with a built-in tire pressure monitoring system.
All Porsche 959s were actually produced at Baur, not at Porsche, on an assembly line with Porsche inspectors overseeing the finished bodies. Most of Porsche's special order interior leather work was also done by the workers at Baur.
The 1983 Frankfurt Motor Show was chosen for the unveiling of the Porsche Group B prototype. Even in the closing hours of October 9, finishing touches were being applied to the car to go on display the next morning. After the first two prototypes, the bodywork was modified to include air vents in the front and rear wheel housings, as well as intake holes behind the doors. The first prototype modified like this was code named "F3", and was destroyed in the first crash test.
The road version of the 959 debuted at the 1985 Frankfurt Motor Show as a 1986 model, but numerous issues delayed production by more than a year. The car was manufactured in two levels of trim, "Sport" and "Komfort", corresponding to the race version and the road version. First customer deliveries of the 959 street variant began in 1987, and the car debuted at a cost of US$225,000 per unit, still less than half what it cost Porsche to build each one. Production ended in 1988 with 292 959s from the assembly line. In total, 337 cars were built, including 37 prototypes and pre-production models. At least one 959 and one 961 remain in the Porsche historic hall in Stuttgart, Germany.
In 1992/1993, Porsche built eight 959s assembled from spare parts from the inventory at the manufacturing site in Zuffenhausen. All eight were "Komfort" versions: four in red and four in silver. These cars were much more expensive (DM 747,500) than the earlier ones (DM 420,000). The later cars also featured a newly developed speed-sensitive damper system. The cars were sold to selected collectors after being driven by works personnel for some time and are today by far the most sought-after 959s.
The 959 was not street legal in the United States prior to 1999 when the "Show and Display" law was passed, although an unknown number were imported via the "grey market" during the late 1980s as show pieces. During the model's development Porsche refused to provide the United States Department of Transportation with the four 959s they required for crash testing, and the car was never certified by the National Highway Traffic Safety Administration for street use in the U.S. In 2001, with the passage of "Show and Display", the crash test requirements were removed and importation of the 959 was allowed, assuming the car could meet the emissions standards applicable in 1987. The 959 can be fitted with a catalytic converter and a re-chipped computer which allows it to meet those emissions requirements. As they are pre-1996 they would not be required to pass any emissions testing anymore: due to the fact that most 959s are now over 25 years old and therefore completely legal for US importation, they are no longer required to comply with show and display laws.
Most owners refuse to modify their 959s, however, and the cars remain collection pieces. Most 959s are in the hands of collectors, but a few do occasionally come to market.